The invention relates to an apparatus for feeding sheet-like blanks of deep-drawable synthetic plastic material to the receiving station of a deep-drawing machine having at least one heatable suction plate. Numerous methods and apparatuses for the manufacture of packagings for flowable media are known, one particular method relating to the manufacture of a packaging which is filled with a flowable medium, e.g., a packaging filled with milk or juice. This packaging element consists of a tube with a bottom and a top wall, all parts being formed from workable synthetic plastic material, preferably by means of a deep-drawing machine. In this respect, it is known that two blanks, each in the form of a flat sheet, are taken from a magazine and fed to one of a plurality of heatable suction plates. Therefore, the heatable suction plate has a separate blank applied to each of its two sides so that the two blanks bear on this suction plate and are heated at a distance from each other.
The further procedural steps in the deep drawing machine, particularly the stepwise heating by contact with a plurality of heatable suction plates, are of no interest where the present invention is concerned, and therefore they will not be described here.
The invention relates to the feeding of the blanks to the heatable suction plate and improvements made to the apparatuses used in this field.
Where the above-described prior art methods are concerned, two magazines to hold the already singled-out blanks are provided on opposite sides of the heatable suction plate or plurality of heatable suction plates. It has been found that it is difficult to bundle sheet-like blanks in large quantities, and furthermore this requires repackaging materials which should be avoided as far as possible. It is known that packaging elements are printed and if already an at least partial print has been applied to the individual blanks, then there is a danger that the print will be wrongly aligned or may even be the wrong way round. During in-house use of the previous manufacturing process, one person was constantly busy loading the deep-drawing machine. This and other handling operations for correctly guiding the blanks from the magazine to the heatable suction plates gave rise to hygiene problems, apart from the higher costs incurred by the handling operations carried out by the aforementioned person until such time as the blanks were singled out.
A man skilled in the art was aware that by producing the deep-drawn package from two shell halves for which one blank had to be fed to each side of the relevant heatable suction plate, it was also necessary to have on each side a magazine to hold blanks and provided with all the mechanical conveying means. Instead of using singled-out blanks, it should have been obvious to work from one web, in which case on each side of the respective heatable suction plate, it would have been necessary to feed a supply roll and a web of deep-drawable synthetic plastic material. Not only would the extra expense of such an installation be considerable but also the risk of the position of the printed part on the then cut off blank being switched round would not have been overcome. Furthermore, the aim of the contractor is to achieve a long effective life of the package producing machine without any interruption in operation for the feeding of raw material. Where supply rolls are concerned, however, the man skilled in the art has no opportunity for continuous conduct of operation without any down time required for roll changing.
Therefore, the invention is based on the problem of so developing an apparatus having the features mentioned at the outset that despite an increase in machine output, production is simplified and operation becomes more able to meet the exacting demands of hygiene.
This problem at least partially entails overcoming the specifically mentioned drawbacks of the prior art devices and of the apparatuses already developed.